Pyrrolidine → tert-Butyl 6-bromo-4-oxospiro[chroman-2,4'-piperidine]-1'-carboxylate
Reaction equation
[CH3:1][C:2]([C:4]1[CH:9]=[C:8]([Br:10])[CH:7]=[CH:6][C:5]=1[OH:11])=[O:3].[C:12]([N:19]1[CH2:24][CH2:23][C:22](=O)[CH2:21][CH2:20]1)([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13].N1CCCC1>CO>[C:15]([O:14][C:12]([N:19]1[CH2:24][CH2:23][C:22]2([CH2:1][C:2](=[O:3])[C:4]3[C:5](=[CH:6][CH:7]=[C:8]([Br:10])[CH:9]=3)[O:11]2)[CH2:21][CH2:20]1)=[O:13])([CH3:18])([CH3:16])[CH3:17]Participants
5
Procedure
A mixture of 2-hydroxy-5-bromoacetophenone (10.75 g, 50 mmol), N—BOC-4-piperidone (9.96 g, 50 mmol) and pyrrolidine (2.09 ml, 25 mmol) in MeOH (80 ml) was heated to reflux for 11 h. The solvent was removed under vacuum and the crude mixture was purified by column chromatography (eluent: hexane/AcOEt 90:10 to 80:20) to give 6-bromo-4-oxo-spiro[chromane-2,4′-piperidine]-1′-carboxylic acid tert-butyl ester (18.55 g) as a yellow solid.
Workup
- temperaturewas heated
- temperatureto reflux for 11 h
- customThe solvent was removed under vacuum
- customthe crude mixture was purified by column chromatography (eluent: hexane/AcOEt 90:10 to 80:20)
Sources & evidence
- ORD record
- ord-87502edf801b438cbd6d303fa7bb8350
- Source dataset
- uspto-grants-2013_11
- Patent number
- US08592444B2
Reaction notes
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